Method of assembling variable valve timing apparatus

ABSTRACT

A method of assembling a variable valve timing apparatus includes steps of temporarily fixing a driven-side rotation body to a base member in a first rotation restricting state by a process of engaging a first projecting and retracting member with the base member of a driving-side rotation body and the driven-side rotation body followed by a process of rotating either the base member or the driven-side rotation body, providing a supplementary member of the driving-side rotation body to the driven-side rotation body to establish a second rotation restricting state by a process of installing the supplementary member to the base member in a state where the second projecting and retracting member engages with the supplementary member and the driven-side rotation body followed by a process of rotating either the supplementary member or the driven-side rotation body, and fastening the supplementary member and the base member by using a fastening member.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is based on and claims priority under 35 U.S.C. §119 toJapanese Patent Application 2012-018682, filed on Jan. 31, 2012 theentire content of which is incorporated herein by reference.

TECHNICAL FIELD

This disclosure generally relates to a method of assembling a variablevalve timing apparatus.

BACKGROUND DISCUSSION

A variable valve timing apparatus including a lock mechanism to lockrelative phase of a driving-side rotation body and a driven-siderotation body at either most retarded angle or most advanced angle isknown. An example of such mechanism is provided with a lock member,which is a projecting and retracting member, on one of the driving-siderotation body and the driven-side rotation body and with a recess forengaging the lock member on the other one of the driving-side rotationbody and the driven-side rotation body. A clearance is provided betweenthe lock member and the recess for engaging the lock member so that thelock member may be inserted into the recess smoothly. In a state wherethe clearance is excessively large, the lock member repeatedly collideswith an inner surface of the recess at a start of an engine andgenerates abnormal noise until an operation chamber is filled withoperation oil. In order to prevent the abnormal noise, an appropriateamount of clearance is required between the projecting and retractingmember and the recess for engaging the projecting and retracting member.

An example of a method of assembling a variable valve timing apparatusdefined with an appropriate amount of clearance between a lock member,which is a projecting and retracting member, and a recess for engagingthe lock member includes a step of locking relative phase of adriven-side rotation body and a rotor body, which is a driving-siderotation body, by making a partition member of the driven-side rotationbody contact with an end surface in a direction of most advanced angleof a fluid chamber, which is formed on an inner peripheral side of therotor body, followed by a step of inserting the lock member into therecess for engaging the lock member formed on a sprocket, which is amember of the driving-side rotation body, and rotating the sprocketrelative to the driven-side rotation body so that the lock member makescontact with an inner surface of the recess for engaging the lockmember, and a step that follows to fasten the sprocket of thedriving-side rotation body and the rotor body in a state where clearancebetween the lock member and the recess for engaging the lock member isappropriately defined by providing a space between the lock member andthe inner surface of the recess by rotating the sprocket and thedriven-side rotation body relative to each other.

A variable valve timing apparatus disclosed in JP2001-241307A,hereinafter referred to as Reference 1, is an example of a variablevalve timing apparatus provided with a lock mechanism that locksrelative phase of a driving-side rotation body and a driven-siderotation body at an intermediate position, which is a position betweenmost retarded angle and most advanced angle. The variable valve timingapparatus disclosed in Reference 1 is an example of a variable valvetiming apparatus provided with restricting members, each of which is aprojecting and retracting member, separately for restricting therelative phase to shift in a direction of retard angle and forrestricting the relative phase to shift in a direction of advance angle.An example of a variable valve timing apparatus provided with two lockmembers, which are projecting and retracting members, serving as a lockmechanism that locks relative phase of a driving-side rotation body anda driven-side rotation body at most retarded angle is also known.

The variable valve timing apparatus disclosed in Reference 1 is providedwith two restricting members, which are projecting and retractingmembers, provided on a front plate of a driving-side rotation body andarranged parallel to an axial direction of the driving-side rotationbody. Grooves to restrict the restricting members are formed on adriven-side rotation body. In a configuration where each of tworestricting members are provided on the front plate, clearance betweenone of the restricting members and the groove corresponding to theaforementioned one of the restricting members is defined in a directionof most retarded angle and clearance between the other restrictingmember and the groove corresponding to the aforementioned otherrestricting member is defined in a direction of most advanced angle.Accordingly, a variable valve timing apparatus provided with a lockmechanism having a multiple number of restricting members, which areprojecting and retracting members, to lock relative phase of thedriving-side rotation body and the driven-side rotation body at anintermediate position is provided with a disadvantage on defining anappropriate amount of clearance between each of the restricting membersand the groove, or recesses for engagement, corresponding to therestricting member. As a result, abnormal noise, which is caused by therestricting members repeatedly colliding with the grooves to restrictthe restriction members by the restricting members changing positionswithin the grooves, is not effectively restricted.

A need thus exists for a method of assembling a variable valve timingapparatus, which is not susceptible to the drawback mentioned above.

SUMMARY

A method of assembling a variable valve timing apparatus includes thevariable timing apparatus that includes a driving-side rotation bodyincluding a base member provided with at least one supplementary member,the driving-side rotation body synchronously rotating with a crankshaftof an internal combustion engine, a driven-side rotation body coaxiallyarranged with the driving-side rotation body and integrally rotatingwith a camshaft for opening and closing valves of the internalcombustion engine, a fluid pressure chamber formed between thedriving-side rotation body and the driven-side rotation body, the fluidpressure chamber divided into an advance chamber and a retard chamber bya partition member provided on at least one of the driving-side rotationbody and the driven-side rotation body, and a first projecting andretracting member and a second projecting and retracting memberselectively engaging with the driving-side rotation body and thedriven-side rotation body to lock relative rotational phase of thedriving-side rotation body and the driven-side rotation body at apredetermined phase or to restrict relative rotational phase of thedriving-side rotation body and the driven-side rotation body within apredetermined range. The method of assembling a variable valve timingapparatus includes steps of temporarily fixing the driven-side rotationbody relative to the base member in a first rotation restricting stateby a process of engaging the first projecting and retracting member withthe base member and the driven-side rotation body followed by a processof rotating either the base member or the driven-side rotation body toestablish a state where the driven-side rotation body rotates in onedirection either in an advance direction or in a retard directionrelative to the base member, providing the supplementary member to thedriven-side rotation body to establish a second rotation restrictingstate by a process of installing the supplementary member to the basemember in a state where the second projecting and retracting memberengages with the supplementary member and the driven-side rotation bodyfollowed by a process of rotating either the supplementary member or thedriven-side rotation body to establish a state where the supplementarymember rotates in said one direction relative to the driven-siderotation body, and fastening the supplementary member and the basemember by a use of a fastening member.

A method of assembling a variable valve timing apparatus includes thevariable valve timing apparatus that includes a driving-side rotationbody including a first driving-side rotation member and a seconddriving-side rotation member, the driving-side rotation bodysynchronously rotating with a crankshaft of an internal combustionengine, a driven-side rotation body coaxially arranged with thedriving-side rotation body and integrally rotating with a camshaft foropening and closing valves of the internal combustion engine, a fluidpressure chamber formed between the driving-side rotation body and thedriven-side rotation body, the fluid pressure chamber divided into anadvance chamber and a retard chamber by a partition member provided onat least one of the driving-side rotation body and the driven-siderotation body, and a first projecting and retracting member and a secondprojecting and retracting member selectively engaging with thedriving-side rotation body and the driven-side rotation body to lockrelative rotational phase of the driving-side rotation body and thedriven-side rotation body at a predetermined phase or to restrictrelative rotational phase of the driving-side rotation body and thedriven-side rotation body within a predetermined range. The method ofassembling a variable valve timing apparatus includes steps oftemporarily fixing the driven-side rotation body in a first rotationrestricting state where rotation of the driven-side rotation body isrestricted to one direction relative to the first driving-side rotationmember following a process of engaging the first projecting andretracting member with the first driving-side rotation member and thedriven-side rotation body, providing the driven-side rotation body tothe second driving-side rotation member to establish a second rotationrestricting state where rotation of the driven-side rotation bodyrelative to the second driving-side rotation member is restricted to theaforementioned one direction or to a direction opposite to theaforementioned one direction following a process of installing thesecond driving-side rotation member to the first driving-side rotationmember in a state where the second projecting and retracting memberengages with the second driving-side rotation member and the driven-siderotation body, and fastening the first driving-side rotation member andthe second driving-side rotation member by a use of a fastening member.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and additional features and characteristics of thisdisclosure will become more apparent from the following detaileddescription considered with the reference to the accompanying drawings,wherein:

FIG. 1 is a cross-sectional view of a variable valve timing apparatusaccording to a first embodiment installed on an engine;

FIG. 2 is a cross-sectional view of the variable valve timing apparatusaccording to the first embodiment in a given state taken along lineII-II in FIG. 1 and viewed from a direction indicated by arrows;

FIG. 3 is a process in a method of assembling the variable valve timingapparatus according to the first embodiment;

FIG. 4 is a process in the method of assembling the variable valvetiming apparatus according to the first embodiment;

FIG. 5 is a process in the method of assembling the variable valvetiming apparatus according to the first embodiment;

FIG. 6 is a cross-sectional view of an outer rotor and an inner rotor ofthe variable valve timing apparatus according to a second embodiment;

FIG. 7 is a process in a method of assembling the variable valve timingapparatus according to the second embodiment;

FIG. 8 is a process in the method of assembling the variable valvetiming apparatus according to the second embodiment; and

FIG. 9 is a process in the method of assembling the variable valvetiming apparatus according to the second embodiment.

DETAILED DESCRIPTION

A method of assembling a variable valve timing apparatus 100 accordingto a first embodiment is described referring to drawings.

As FIGS. 1 and 2 illustrate, the variable valve timing apparatus 100includes an outer rotor 1, which serves as an example of a driving-siderotation body. The outer rotor 1 rotates in a rotational direction Sshown in FIG. 2 synchronously with a crankshaft C of an engine E, whichserves as an internal combustion engine. The variable valve timingapparatus 100 also includes an inner rotor 3, which serves as an exampleof a driven-side rotation body. The inner rotor 3 is rotationallysupported to an inner periphery of the outer rotor 1 such that the innerrotor 3 rotates relative to the outer rotor 1. The inner rotor 3integrally rotates with a camshaft 2 that opens and closes valves of theengine E.

The outer rotor 1 includes a front plate 4 arranged at a frontwardposition of the outer rotor 1, which is a position in an oppositedirection to where the camshaft 2 is arranged relative to the outerrotor 1. The outer rotor 1 also includes a sprocket 5 arranged at arearward position of the outer rotor 1, which is a position in adirection of the camshaft 2. The outer rotor 1 further includes a rotorbody 6 placed between the front plate 4 and the sprocket 5. The rotorbody 6 serves as a base member. Each of the front plate 4 and thesprocket 5 serves as a supplementary member.

In a state where the crankshaft C is driven to rotate, rotationaldriving force from the crankshaft C is transmitted to the sprocket 5 viaa power transmission member CH so that the outer rotor 1 is driven torotate in the rotational direction S shown in FIG. 2. Rotation of theouter rotor 1 drives rotation of the inner rotor 3 in the rotationaldirection S so that the camshaft 2 rotates. Rotation of the camshaft 2makes cams provided on the camshaft 2 to press down valves of the engineE. An example of the valves is an intake valve.

As FIG. 2 illustrates, a multiple number of first partition members 8are provided on an inner peripheral portion of the rotor body 6. Each ofthe first partition members 8, which serves as a partition member,protrudes radially inward from the inner peripheral portion of the rotorbody 6. The first partition members 8 are arranged such that each of thefirst partition members 8 is spaced apart from each other in a directionthat conforms to the rotational direction S. A multiple number of secondpartition members 9 are provided on an outer peripheral portion of theinner rotor 3. Each of the second partition members 9, which serves as apartition member, protrudes radially outward from the outer peripheralportion of the inner rotor 3. Similarly to the first partition members8, the second partition members 9 are arranged such that each of thesecond partition members 9 is spaced apart from each other in adirection that conforms to the rotational direction S. The firstpartition members 8 divide a space between the rotor body 6 and theinner rotor 3 into a multiple number of fluid pressure chambers 10. Eachof the second partition members 9 divides each of the fluid pressurechambers 10 into an advance chamber 11 and a retard chamber 12.

As FIGS. 1 and 2 illustrate, flow paths 13 for advance angle and flowpaths 14 for retard angle are formed within the inner rotor 3 and thecamshaft 2. The flow paths 13 for advance angle connect each of theadvance chambers 11 and a fluid supply and discharge mechanism 20 thatcontrols supplying and discharging of operation oil and interrupting ofsupply and discharge of the operation oil. The flow paths 14 for retardangle connect each of the retard chambers 12 and the fluid supply anddischarge mechanism 20.

The fluid supply and discharge mechanism 20 includes an oil pan, an oilpump P, fluid control valves V and an electronic control unit ECU. Thefluid control valve V regulates supplying and discharging of theoperation oil and interrupting of supply and discharge of the operationoil to the advance chamber 11 and the retard chamber 12. The electroniccontrol unit ECU controls operations of the fluid control valves V. Bycontrolling the electronic control unit ECU, relative rotational phaseof the inner rotor 3 and the outer rotor 1 is shifted to an advancedirection, which is a rotational direction indicated with S1 in FIG. 2,shifted to a retard direction, which is a rotational direction indicatedwith S2 in FIG. 2, or maintained at a selected phase.

As FIG. 1 illustrates, a torsion spring 19 is provided between the innerrotor 3 and the outer rotor 1 as a biasing mechanism that biases therelative rotational phase of the outer rotor 1 and the inner rotor 3toward the direction of advance angle. The torsion spring 19 biases theinner rotor 3 relative to the outer rotor 1 in the rotational directionindicated as S1, which is toward the advance direction. Accordingly, thetorsion spring 19 restricts relative phase of the inner rotor 3 thatintegrally rotates with the camshaft 2 from lagging relative to rotationof the outer rotor 1 due to a resistance force the camshaft 2 receivesfrom valve springs.

As FIGS. 1 and 2 illustrate, a lock mechanism of the variable valvetiming apparatus 100 according to the first embodiment includes a firstprojecting and retracting member 21 installed on one of the firstpartition member 8 of the rotor body 6 and a second projecting andretracting member 22 installed on the inner rotor 3 arranged such thatthe second projecting and retracting member 22 projects and retractsfrom a surface facing the sprocket 5 in a direction parallel to arotational axis X. The lock mechanism also includes a first recess 23for engagement formed on an outer peripheral surface of the inner rotor3 in a state where a recessed portion, or a groove, forms an arc havinga center at the rotational axis X. The first recess 23 for engagement iswhere the first projecting and retracting member 21 engages. The secondrecess 24 for engagement where the second projecting and retractingmember 22 engages is formed on the sprocket 5 on a surface facing theinner rotor 3.

The first projecting and retracting member 21 is a component thatprojects and retracts to restrict the relative rotational phase of theouter rotor 1 and the inner rotor 3 to shift in the retard direction.The second projecting and retracting member 22 is a component thatprojects and retracts to restrict the relative rotational phase to shiftin the advance direction. A base portion of the first projecting andretracting member 21 is arranged at a first housing portion 30 formed onthe first partition member 8 of the rotor body 6. The first housingportion 30 is provided with a first spring 25 that biases the firstprojecting and retracting member 21 to project in a direction toward theinner rotor 3. A base portion of the second projecting and retractingmember 22 is arranged at a second housing portion 31 formed on the innerrotor 3. The second housing portion 31 is provided with a second spring26 that biases the second projecting and retracting member 22 to projectin a direction toward the sprocket 5. The first projecting andretracting member 21 is a plate form locking piece or a component havinga similar form. The second projecting and retracting member 22 is astick form lock pin or a component having a similar form. A stick formlock pin may be appropriately used as the first projecting andretracting member 21 instead of the plate form locking piece.

Within the inner rotor 3 and the camshaft 2, first flow paths fordisengagement, which are flow paths 14 for retard angle, and a secondflow path 17 for disengagement are provided. The first flow paths fordisengagement connect to the fluid supply and discharge mechanism 20 ina state where the first flow paths for disengagement and a bottomsurface of the first recess 23 for engagement communicate. The secondflow path 17 for disengagement connects to the fluid supply anddischarge mechanism 20 in a state where the second flow path 17 fordisengagement and a portion near the second projecting and retractingmember 22 communicate. In a state where the first flow paths fordisengagement, which is the flow paths 14 for retard angle, is providedwith the operation oil, the first projecting and retracting member 21retracts from the first recess 23 for engagement against biasing forceof the first spring 25. In other words, the first projecting andretracting member 21 switches to an unlocked posture. In a state wherethe second flow path 17 for disengagement is provided with the operationoil, the second projecting and retracting member 22 retracts from thesecond recess 24 for engagement against biasing force of the secondspring 26. In other words, the second projecting and retracting member22 switches to an unlocked posture.

By engaging the first projecting and retracting member 21 to the firstrecess 23 for engagement, a rotation range of the inner rotor 3 relativeto the outer rotor 1 from an intermediate lock phase in a direction ofthe retard angle, which is the rotational direction S2 in FIG. 2, isrestricted. By engaging the second projecting and retracting member 22to the second recess 24 for engagement, a rotation range of the innerrotor 3 relative to the outer rotor 1 from the intermediate lock phasein the advance direction, which is the rotational direction indicated asS1 in FIG. 2, is restricted.

The method of assembling the variable valve timing apparatus 100according to the first embodiment is described next. The method includesa first step of temporarily fixing the inner rotor 3 relative to therotor body 6 in a first rotation restricting state by a process ofsetting the sprocket 5, the rotor body 6, the inner rotor 3, and thefront plate 4 on a jig and engaging the first projecting and retractingmember 21 with the rotor body 6 and the inner rotor 3 followed by aprocess of rotating either the rotor body 6 or the inner rotor 3relative to the other one of the rotor body 6 or the inner rotor 3either in one direction of advance direction S1 or retard direction S2to establish a state where the inner rotor 3 rotates in one directioneither in the advance direction S1 or in the retard direction S2relative to the rotor body 6, which serves as the base member, of theouter rotor 1. Here, the first rotation restricting state is the statewhere the first projecting and retracting member 21 and an end surface23 a of the first recess 23 for engagement in the direction of advanceangle are in contact with each other.

The method includes a second step of providing the sprocket 5 to theinner rotor 3 to establish a second rotation restricting state, as FIG.4 illustrates, by a process illustrated in FIG. 3 of installing thesprocket 5 to the rotor body 6 in a state where the second projectingand retracting member 22 engages with the sprocket 5 and the inner rotor3 followed by a process of rotating the sprocket 5 relative to the innerrotor 3 either in one direction of advance direction S1 or retarddirection S2 to establish a state where the sprocket 5, which serves asa supplementary member of the outer rotor 1, rotates in theaforementioned one direction described in the first step relative to theinner rotor 3. Here, the second rotation restricting state is the statewhere the second projecting and retracting member 22 and an end surface24 a of the second recess 24 for engagement in the direction of advanceangle are in contact with each other. As an example, the second rotationrestricting state may be established by rotating the sprocket 5 relativeto the inner rotor 3 so that the second projecting and retracting member22 comes into contact with the end surface 24 a of the second recess 24for engagement in the direction of advance angle.

The method includes a third step of fastening the rotor body 6, whichserves as the base member of the outer rotor 1, and the front plate 4and the sprocket 5, each of which serves as a supplementary member, byusing bolts or similar fastening members 40 following a process ofdefining a predetermined amount of clearance L between the secondprojecting and retracting member 22 and the end surface 24 a of thesecond recess 24 for engagement in the direction of advance angle, asFIG. 5 illustrates. The sprocket 5 may be easily rotated relative to therotor body 6 and the inner rotor 3 by providing a worm gear, or asimilar device, to gear with a tooth portion at the outer periphery ofthe sprocket 5.

The first projecting and retracting member 21 and the second projectingand retracting member 22 are assembled so that rotation of the innerrotor 3 is restricted by different members of the outer rotor 1, whichare the rotor body 6 and the sprocket 5. Accordingly, a state ofengagement between each of a multiple number of projecting andretracting members 21, 22 and either the outer rotor 1 or the innerrotor 3 are independently adjusted so that the outer rotor 1 and theinner rotor 3 are fastened in a state where the state of engagement isappropriately established for each of the projecting and retractingmembers 21, 22. As a result, noise generated at a start of the engine,which is caused by the projecting and retracting members 21, 22colliding with the recesses 23, 24, is effectively reduced.

In the method of assembling the variable valve timing apparatus 100according to the first embodiment, the sprocket 5 is provided to theinner rotor 3 to establish the second rotation restricting state by aprocess of rotating the sprocket 5 in the direction of retard anglerelative to the inner rotor 3 to make the end surface 24 a of the secondrecess 24 for engagement in the direction of advance angle and thesecond projecting and retracting member 22 contact with each other,followed by a process of rotating the sprocket 5 in a direction oppositeto the aforementioned one direction to a predetermined amount so thatclearance L is defined between the second projecting and retractingmember 22 and the end surface 24 a of the second recess 24 forengagement in the direction of advance angle.

Through a process of rotating the sprocket 5 relative to the inner rotor3 in one direction to establish the second rotation restricting statefollowed by a process of rotating, for example, the sprocket 5 in thedirection opposite to the aforementioned one direction to thepredetermined amount, the appropriate amount of clearance L between thesecond projecting and retracting member 22 and the end surface 24 a ofthe second recess 24 for engagement in the direction of advance angle isdefined. In a state described herewith, assembling the outer rotor 1provides appropriately defined clearances such that the first projectingand retracting member 21 and the second projecting and retracting member22 smoothly operate. While providing smooth operations of the firstprojecting and retracting member 21 and the second projecting andretracting member 22, the arrangement described herewith provides thevariable valve timing apparatus 100 with a state where minimum amount ofallowance is available for the variable valve timing apparatus 100 thatis locked in an intermediate lock position.

Furthermore, the variable valve timing apparatus 100 according to thefirst embodiment is provided with the first projecting and retractingmember 21 formed in a key form arranged to project and retract in aradial direction of the outer rotor 1 and with the second projecting andretracting member 22 formed in a pin form arranged to project andretract in an axial direction of the outer rotor 1. With the firstprojecting and retracting member 21 formed in the key form arranged toproject and retract in the radial direction of the outer rotor 1, thefirst projecting and retracting member 21 selectively engaging with theouter rotor 1 and the inner rotor 3, each of stop positions of the innerrotor 3, which are a stop position in the direction of retard angle, astop position in the direction of advance angle and the intermediatelock position, may be defined on the rotor body 6, which is an elementof the outer rotor 1 that serves as the base member. In other words,upon the arrangement described herewith, fixing the first projecting andretracting member 21 at the intermediate lock position may automaticallydefine the stop positions in the directions of retard angle and advanceangle. In addition, because the front plate 4 is a separate memberindependent of the first projecting and retracting member 21 and thesecond projecting and retracting member 22, and a process to considerthe stop positions in the directions of retard angle and advance anglemay be omitted at a time the first projecting and retracting member 21is maintained in a contact state with the rotor body 6 to provide theintermediate lock position, the front plate 4 may be assembled to therotor body 6, which is a base portion of the outer rotor 1, withoutconsiderations for positioning relative to the rotor body 6. As aresult, upon the arrangement described herewith, an assembly process ofthe outer rotor 1 may be simplified so that the variable valve timingapparatus 100 may be economically assembled.

A method of assembling a variable valve timing apparatus 100 accordingto a second embodiment is described next. As FIGS. 6 to 9 illustrate, alock mechanism of the variable valve timing apparatus 100 according tothe second embodiment includes a first projecting and retracting member21 and a second projecting and retracting member 22 provided on theinner rotor 3 arranged such that each of the first projecting andretracting member 21 and the second projecting and retracting member 22projects and retracts in a direction parallel to a rotational axis X. Onthe front plate 4 on a surface facing an inner rotor 3, a first recess23 for engagement, which is where the first projecting and retractingmember 21 engages, is provided. On a sprocket 5 on a surface facing theinner rotor 3, a second recess 24 for engagement, which is where thesecond projecting and retracting member 22 engages, is provided.

The first recess 23 for engagement receives an end portion of the firstprojecting and retracting member 21 that projects in the direction ofthe front plate 4. The second recess 24 for engagement receives an endportion of the second projecting and retracting member 22 that projectsin the direction of the sprocket 5.

As FIG. 7 illustrates, a base portion of the first projecting andretracting member 21 is arranged at a first housing portion 30 formed onthe inner rotor 3. The first housing portion 30 is provided with a firstspring 25 that biases the first projecting and retracting member 21 toproject in a direction toward the front plate 4. A base portion of thesecond projecting and retracting member 22 is arranged at a secondhousing portion 31 formed on the inner rotor 3. The second housingportion 31 is provided with a second spring 26 that biases the secondprojecting and retracting member 22 to project in a direction toward thesprocket 5.

Within the inner rotor 3 and the camshaft 2, a third flow path 16 fordisengagement and a second flow path 17 for disengagement are provided.The third flow path 16 for disengagement connects to the fluid supplyand discharge mechanism 20 in a state where the third flow path 16 fordisengagement and a portion near the first recess 23 for engagementcommunicate. The second flow path 17 for disengagement connects to thefluid supply and discharge mechanism 20 in a state where the second flowpath 17 for disengagement and a portion near the second projecting andretracting member 22 communicate. In a state where the third flow path16 for disengagement is provided with operation oil, the firstprojecting and retracting member 21 retracts from the first recess 23for engagement against biasing force of the first spring 25. In otherwords, the first projecting and retracting member 21 switches to anunlocked posture. In a state where the second flow path 17 fordisengagement is provided with the operation oil, the second projectingand retracting member 22 retracts from the second recess 24 forengagement against biasing force of the second spring 26. In otherwords, the second projecting and retracting member 22 switches to anunlocked posture.

The method of assembling the variable valve timing apparatus 100according to the second embodiment is described next. The methodincludes, as FIG. 7 illustrates, a first step of temporarily fixing theinner rotor 3 in a first rotation restricting state relative to thefront plate 4 by a process of setting the sprocket 5, the rotor body 6,the inner rotor 3, and the front plate 4 on a jig and engaging the firstprojecting and retracting member 21 with the front plate 4 and the innerrotor 3 followed by a process of rotating either one of the front plate4 or the inner rotor 3 relative to the other one of the front plate 4 orthe inner rotor 3 either in one direction of advance direction S1 orretard direction S2 to establish a state where the inner rotor 3 rotatesin one direction either in the advance direction S1 or in the retarddirection S2 relative to the rotor body 6, which serves as the basemember of the outer rotor 1. Here, the first rotation restricting stateis the state where the first projecting and retracting member 21 and anend surface 23 a of the first recess 23 for engagement in the directionof retard angle, the first recess 23 formed on the front plate 4, are incontact with each other. Note that each of the rotor body 6 and thefront plate 4 serves as a first driving-side rotation member and thesprocket 5 serves as a second driving-side rotation member.

The method includes, as FIG. 8 illustrates, a second step of providingthe inner rotor 3 to the sprocket 5 to establish a second rotationrestricting state by a process of installing the sprocket 5 to the rotorbody 6 in a state where the second projecting and retracting member 22engages with the sprocket 5 and the inner rotor 3, followed by a processof rotating the sprocket 5 relative to the inner rotor 3 either in onedirection of advance direction S1 or retard direction S2 to provide astate where the sprocket 5, which serves as a supplementary member ofthe outer rotor 1, rotates in the aforementioned one direction describedin the first step relative to the inner rotor 3. Here, the secondrotation restricting state is the state where the second projecting andretracting member 22 and an end surface 24 a of the second recess 24 forengagement in the direction of advance angle are in contact with eachother. As an example, the second rotation restricting state may beestablished by rotating the sprocket 5 relative to the inner rotor 3 sothat the second projecting and retracting member 22 comes into contactwith the end surface 24 a of the second recess 24 for engagement in thedirection of advance angle.

The method includes, as FIG. 9 illustrates, a third step of fasteningthe rotor body 6, which serves as the base member of the outer rotor 1,and the front plate 4 and the sprocket 5, each of which serves as asupplementary member, by using bolts or similar fastening members 40following a process of defining a predetermined amount of clearance Lbetween the second projecting and retracting member 22 and the endsurface 24 a of the second recess 24 for engagement in the direction ofadvance angle followed by another process of defining clearance betweenthe first projecting and retracting member 21 and an end surface 23 a ofthe first recess 23 for engagement in the direction of retard angle asnecessary.

In the method of assembling the variable valve timing apparatus 100according to the second embodiment, the second rotation restrictingstate is established by providing the inner rotor 3 to the sprocket 5 bya process of rotating the sprocket 5 in the direction of retard anglerelative to the inner rotor 3 to make the end surface 24 a of the secondrecess 24 for engagement in the direction of advance angle and thesecond projecting and retracting member 22 contact with each otherfollowed by a process of rotating the sprocket 5 in the oppositedirection relative to the inner rotor 3 to a predetermined amount sothat clearance L is defined between the second projecting and retractingmember 22 and the end surface 24 a of the second recess 24 forengagement in the direction of advance angle. Furthermore, the firstrotation restricting state is established by providing the inner rotor 3to the front plate 4 by a process of rotating the front plate 4 in thedirection of advance angle relative to the inner rotor 3 to make the endsurface 23 a of the first recess 23 for engagement in the direction ofretard angle and the first projecting and retracting member 21 contactwith each other followed by a process of rotating the front plate 4 inthe opposite direction relative to the inner rotor 3 to a predeterminedamount so that clearance is defined between the first projecting andretracting member 21 and the end surface 23 a of the first recess 23 forengagement in the direction of retard angle.

Through a process of rotating each of the sprocket 5 and the front plate4 in one direction relative to the inner rotor 3 and fixing each of thesprocket 5 and the front plate 4 in a locked state where rotation isrestricted relative to the inner rotor 3, followed by a process ofrotating, for example, the sprocket 5 and the front plate 4 in theopposite direction relative to the inner rotor 3 by the predeterminedamount, the appropriate amount of clearance between each of theprojecting and retracting members 21, 22 and the recesses 23, 24 forengagement corresponding to each of the projecting and retractingmembers 21, 22 is defined. In a state described herewith, assembling theouter rotor 1 provides appropriately defined clearances such that thefirst projecting and retracting member 21 and the second projecting andretracting member 22 smoothly operate. While providing smooth operationsof the first projecting and retracting member 21 and the secondprojecting and retracting member 22 the arrangement described herewithprovides the variable valve timing apparatus 100 with a state whereminimum amount of allowance is available for the variable valve timingapparatus 100 that is locked in the intermediate lock position.

Methods of assembling a variable valve timing apparatus 100 according toother embodiments are described next. The method of assembling thevariable valve timing apparatus 100 according to this disclosure mayinclude a variable valve timing apparatus 100 provided with firstpartition members 8 that form fluid pressure chambers 10 on an innerrotor 3, which serves as a driven-side rotation body, instead of on aninner peripheral portion of an outer rotor 1, which serves as adriving-side rotation body. Accordingly, second partition members 9 thatdivide the fluid pressure chambers 10 into advance chambers 11 andretard chambers 12 may be provided on the outer rotor 1, which serves asthe driving-side rotation body.

The method of assembling the variable valve timing apparatus 100according to this disclosure may include a variable valve timingapparatus 100 provided with housing portions 30, 31, each of which iswhere either a first projecting and retracting member 21 or a secondprojecting and retracting member 22 is arranged with, on either theouter rotor 1, which serves as the driving-side rotation body, or theinner rotor 3, which serves as the driven-side rotation body.

The method of assembling variable valve timing apparatus 100 accordingto the first embodiment may include a variable valve timing apparatus100 provided with a second projecting and retracting member 22 arrangedto engage with either a front plate 4 or the inner rotor 3. The variablevalve timing apparatus 100 according to this disclosure may be providedwith a rear plate instead of a sprocket 5 and a second projecting andretracting member 22 or a second recess 24 for engagement may beprovided on the rear plate. In a state where the rear plate is providedas such, the sprocket 5 is provided on the outer peripheral portion ofthe rotor body 6.

The method of assembling the variable valve timing apparatus 100according to the second embodiment is an example of a method ofassembling a variable valve timing apparatus 100 including a process oftemporarily fixing the first projecting and retracting member 21 and thefirst recess 23 for engagement provided in a direction of the frontplate 4, followed by a process of restricting rotation of the secondprojecting and retracting member 22 and the second recess 24 forengagement provided in a direction of the sprocket 5. Nevertheless, theaforementioned processes may be switched so that a process oftemporarily fixing the second projecting and retracting member 22 andthe second recess 24 for engagement provided in the direction of thesprocket 5 is followed by a process of restricting rotation of the firstprojecting and retracting member 21 and the first recess 23 forengagement provided in the direction of the front plate 4.

The method of assembling the variable valve timing apparatus 100according to this disclosure includes the variable valve timingapparatus 100 separately provided with a projecting and retractingmember for restricting the relative phase of a driving-side rotationbody and a driven-side rotation body at most retarded angle and aprojecting and retracting member for restricting the relative phase ofthe driving-side rotation body and the driven-side rotation body at mostadvanced angle. Nevertheless, the method of assembling the variablevalve timing apparatus 100 according to this disclosure may include thevariable valve timing apparatus 100 provided with a lock mechanismhaving a multiple number of projecting and retracting members forlocking the relative phase of the driving-side rotation body and thedriven-side rotation body at either most retarded angle or most advancedangle.

The method of assembling the variable valve timing apparatus 100according to this disclosure may be applied to a variable valve timingapparatus for an internal combustion engine of an automobile and otherdevices.

According to an aspect of this disclosure, a method of assembling thevariable valve timing apparatus 100 includes the variable valve timingapparatus 100, which includes the outer rotor 1 including the rotor body6 provided with at least one of the front plate 4 and the sprocket 5,the outer rotor 1 synchronously rotating with the crankshaft C of theinternal combustion engine E, the inner rotor 3 coaxially arranged withthe outer rotor 1 and integrally rotating with the camshaft 2 foropening and closing valves of the internal combustion engine E, thefluid pressure chamber 10 formed between the outer rotor 1 and the innerrotor 3, the fluid pressure chamber 10 divided into the advance chamber11 and the retard chamber 12 by the partition member 8, 9 provided on atleast one of the outer rotor 1 and the inner rotor 3, and the firstprojecting and retracting member 21 and the second projecting andretracting member 22 selectively engaging with the outer rotor 1 and theinner rotor 3 to lock relative rotational phase of the outer rotor 1 andthe inner rotor 3 at a predetermined phase or to restrict relativerotational phase of the outer rotor 1 and the inner rotor 3 within apredetermined range. The method of assembling the variable valve timingapparatus 100 includes steps including the steps of temporarily fixingthe inner rotor 3 relative to the rotor body 6 in the first rotationrestricting state by a process of engaging the first projecting andretracting member 21 with the rotor body 6 and the inner rotor 3followed by a process of rotating either the rotor body 6 or the innerrotor 3 to establish a state where the inner rotor 3 rotates in onedirection either in the advance direction S1 or in the retard directionS2 relative to the rotor body 6, providing the front plate 4 or thesprocket 5 to the inner rotor 3 to establish the second rotationrestricting state by a process of installing the front plate 4 or thesprocket 5 to the rotor body 6 in a state where the second projectingand retracting member 22 engages with the front plate 4 or the sprocket5 and the inner rotor 3 followed by a process of rotating one of theinner rotor 3 and either the front plate 4 or the sprocket 5 toestablish a state where the front plate 4 or the sprocket 5 rotates inthe aforementioned one direction relative to the inner rotor 3, andfastening the front plate 4, the sprocket 5, and the rotor body 6 by ause of the fastening member 40.

Accordingly, each of the first projecting and retracting member 21 andthe second projecting and retracting member 22 is installed such thatrotation of the inner rotor 3 is independently restricted by a differentmember of the outer rotor 1, which is the rotor body 6, the front plate4, or the sprocket 5. Upon the arrangement described herewith, while anamount of clearance is adjusted between one of the projecting andretracting members 21, 22 and either the outer rotor 1 or the innerrotor 3, which is where the aforementioned one of the projecting andretracting members 21, 22 is received, an amount of clearance definedbetween the other one of the projecting and retracting members 21, 22and either the outer rotor 1 or the inner rotor 3, which is where theother one of the aforementioned one of the projecting and retractingmembers 21, 22 is received, remains unchanged. In a state whereadjustment of clearance between each of a multiple number of projectingand retracting members 21, 22 and either the outer rotor 1 or the innerrotor 3 is independent of each other, the outer rotor 1 and the innerrotor 3 may be fastened in a state where clearance is appropriatelydefined for each of the projecting and retracting members 21, 22. As aresult, noise generated at the start of the engine, which is caused bythe projecting and retracting members 21, 22 colliding with the recesses23, 24 for engagement, is effectively reduced.

According to another aspect of this disclosure, the method of assemblingthe variable valve timing apparatus 100 includes the variable valvetiming apparatus 100 including one of the first projecting andretracting member 21 and the second projecting and retracting member 22formed in a key form arranged to project and retract in the radialdirection of the outer rotor 1 and the other one of the first projectingand retracting member 21 and the second projecting and retracting member22 formed in a pin form arranged to project and retract in the axialdirection of the outer rotor 1.

In a situation where each of the first projecting and retracting member21 and the second projecting and retracting member 22 is formed in a pinform moving in the axial direction of the rotational axis X, the firstprojecting and retracting member 21 engages with the front plate 4 ofthe outer rotor 1 and the second projecting and retracting member 22engages with a rear side plate of the outer rotor 1, for example thesprocket 5 or the rear plate. In most cases, a stop position in thedirection of retard angle and a stop position in the direction ofadvance angle are formed on a base portion of the outer rotor 1 having atubular form. The base portion may be provided as a separate component,for example as the rotor body 6, in addition to the front plate 4 andthe rear side plate. On assembling components of the outer rotor 1 andthe inner rotor 3 into a variable valve timing apparatus 100, assemblyprocess includes processes of defining the intermediate lock position,the stop position in the direction of the retard angle, and the stopposition in the direction of the advance angle. In order toappropriately define each of the intermediate lock position, the stopposition in the direction of the retard angle, and the stop position inthe direction of the advance angle, each of the front plate 4 and therear side plate where either one of the first projecting and retractingmember 21 or the second projecting and retracting member 22 engages isassembled to an appropriate position in consideration of where the innerrotor 3 makes contact with the base portion of the outer rotor 1 in eachof the directions of retard angle and the advance angle. In other words,the assembly process includes careful positioning of each relatingcomponent. On the other hand, in a situation where, for example, thefirst projecting and retracting member 21 is formed in the key formarranged to project and retract in the radial direction of the outerrotor 1, the first projecting and retracting member 21 selectivelyengaging with the outer rotor 1 and the inner rotor 3, each of the stoppositions of the inner rotor 3, which are the stop position in thedirection of the retard angle, the stop position in the direction of theadvance angle and the intermediate lock position, may be defined on thebase portion alone, the base portion that is an element of the outerrotor 1. In other words, upon the arrangement described herewith, fixingthe first projecting and retracting member 21 at the intermediate lockposition automatically defines the stop positions in the directions ofretard angle and advance angle. In addition, in a situation where aseparate component independent of the first projecting and retractingmember 21 and the second projecting and retracting member 22 isprovided, for example a rear side plate, because such component does notrequire a process to consider the stop positions in the directions ofretard angle and advance angle at a time the first projecting andretracting member 21 is maintained in a contact state with the rotorbody 6 to provide the intermediate lock position, such component may beassembled to the base portion of the outer rotor 1 withoutconsiderations for positioning relative to the base portion.Accordingly, the assembly process of the outer rotor 1 may be simplifiedso that the variable valve timing apparatus 100 may be economicallyassembled.

According to further aspect of this disclosure, the method of assemblingthe variable valve timing apparatus 100 includes the step of fasteningthe front plate 4, the sprocket 5, and the rotor body 6 by the use ofthe fastening member 40, the step following a process of defining apredetermined amount of clearance L between the second projecting andretracting member 22 and either the front plate 4 or the sprocket 5.

In a state where clearance between either one of the projecting andretracting members 21, 22 and either the front plate 4 or the sprocket 5is large, noise caused by the projecting and retracting members 21, 22colliding with the recesses 23, 24 for engagement, increases. In a statewhere clearance between either one of the projecting and retractingmembers 21, 22 and either the front plate 4 or the sprocket 5 is small,smoothness reduces on engaging each of the projecting and retractingmembers 21, 22 to either the outer rotor 1 or the inner rotor 3 and ondisengaging each of the projecting and retracting members 21, 22 fromeither the outer rotor 1 or the inner rotor 3. Upon the arrangementdescribed herewith, fastening the front plate 4, the sprocket 5, and therotor body 6 by the use of the fastening member 40 after definingpredetermined amount of clearance L between the second projecting andretracting member 22 and either the front plate 4 or the sprocket 5provides an appropriate amount of clearance L between the secondprojecting and retracting members 22 and either the front plate 4 or thesprocket 5. Accordingly, while maintaining smooth operation of theprojecting and retracting members 21, 22, noise caused by the projectingand retracting members 21, 22 colliding with the recesses 23, 24 forengagement, is effectively reduced.

According to another aspect of this disclosure, the method of assemblingthe variable valve timing apparatus 100 includes the variable valvetiming apparatus 100, which includes the outer rotor 1 including therotor body 6, the front plate 4, and the sprocket 5, the outer rotor 1synchronously rotating with the crankshaft C of the internal combustionengine E, the inner rotor 3 coaxially arranged with the outer rotor 1and integrally rotating with the camshaft 2 for opening and closingvalves of the internal combustion engine E, the fluid pressure chamber10 formed between the outer rotor 1 and the inner rotor 3, the fluidpressure chamber 10 divided into the advance chamber 11 and the retardchamber 12 by the partition member 8, 9 provided on at least one of theouter rotor 1 and the inner rotor 3, and the first projecting andretracting member 21 and a second projecting and retracting member 22selectively engaging with the outer rotor 1 and the inner rotor 3 tolock relative rotational phase of the outer rotor 1 and the inner rotor3 at a predetermined phase or to restrict relative rotational phase ofthe outer rotor 1 and the inner rotor 3 within a predetermined range.The method of assembling the variable valve timing apparatus 100includes steps including the steps of temporarily fixing the inner rotor3 in the first rotation restricting state where rotation of the innerrotor 3 is restricted to one direction relative to either the frontplate 4 or the rotor body 6 following a process of engaging the firstprojecting and retracting member 21 with the inner rotor 3 and eitherthe front plate 4 or the rotor body 6, providing the inner rotor 3 toeither the front plate 4 or the sprocket 5 to establish the secondrotation restricting state where rotation of the inner rotor 3 relativeto either the front plate 4 or the sprocket 5 is restricted to theaforementioned one direction or to a direction opposite to theaforementioned one direction following a process of installing eitherthe front plate 4 or the sprocket 5 to the rotor body 6 in a state wherethe second projecting and retracting member 22 engages with the innerrotor 3 and either the front plate 4 or the sprocket 5, and fasteningthe rotor body 6, the front plate 4, and the sprocket 5 by a use of thefastening member 40.

Accordingly, each of the first projecting and retracting member 21 andthe second projecting and retracting member 22 is installed such thatrotation of the inner rotor 3 is independently restricted by a differentmember of the outer rotor 1, which is the rotor body 6, the front plate4 or the sprocket 5. Upon the arrangement described herewith, while anamount of clearance is adjusted between one of the projecting andretracting members 21, 22 and either the outer rotor 1 or the innerrotor 3, which is where the aforementioned one of the projecting andretracting members 21, 22 is received, an amount of clearance definedbetween the other one of the projecting and retracting members 21, 22and either the outer rotor 1 or the inner rotor 3, which is where theother one of the aforementioned one of the projecting and retractingmembers 21, 22 is received, remains unchanged. In a state whereadjustment of clearance between each of a multiple number of projectingand retracting members 21, 22 and either the outer rotor 1 or the innerrotor 3 is independent or each other, the outer rotor 1 and the innerrotor 3 may be fastened in a state where clearance is appropriatelydefined for each of the projecting and retracting members 21, 22. As aresult, noise generated at the start of the engine, which is caused bythe projecting and retracting members 21, 22 colliding with the recesses23, 24 for engagement, is effectively reduced.

According to further aspect of this disclosure, the method of assemblingthe variable valve timing apparatus 100 includes the step of fasteningthe rotor body 6, the front plate 4, and the sprocket 5 by the use ofthe fastening member 40, the step following a process of defining apredetermined amount of clearance L between the second projecting andretracting member 22 and either the front plate 4 or the sprocket 5.

In a state where clearance between either one of the projecting andretracting members 21, 22 and either the front plate 4 or the sprocket 5is large, noise caused by the projecting and retracting members 21, 22colliding with the recesses 23, 24 for engagement, increases. In a statewhere clearance between either one of the projecting and retractingmembers 21, 22 and either the front plate 4 or the sprocket 5 is small,smoothness reduces on engaging each of the projecting and retractingmembers 21, 22 to either the outer rotor 1 or the inner rotor 3 and ondisengaging each of the projecting and retracting members 21, 22 fromeither the outer rotor 1 or the inner rotor 3. Upon the arrangementdescribed herewith, fastening the front plate 4, the sprocket 5, and therotor body 6 by the use of the fastening member 40 after definingpredetermined amount of clearance L between the second projecting andretracting member 22 and either the front plate 4 or the sprocket 5provides an appropriate amount of clearance L between the secondprojecting and retracting member 22 and either the front plate 4 or thesprocket 5. Accordingly, while maintaining smooth operation of theprojecting and retracting members 21, 22, noise caused by the projectingand retracting members 21, 22 colliding with the recesses 23, 24 forengagement, is effectively reduced.

The principles, preferred embodiment and mode of operation of thepresent invention have been described in the foregoing specification.However, the invention which is intended to be protected is not to beconstrued as limited to the particular embodiments disclosed. Further,the embodiments described herein are to be regarded as illustrativerather than restrictive. Variations and changes may be made by others,and equivalents employed, without departing from the spirit of thepresent invention. Accordingly, it is expressly intended that all suchvariations, changes and equivalents which fall within the spirit andscope of the present invention as defined in the claims, be embracedthereby.

1. A method of assembling a variable valve timing apparatus comprising adriving-side rotation body including a base member provided with atleast one supplementary member, the driving-side rotation bodysynchronously rotating with a crankshaft of an internal combustionengine, a driven-side rotation body coaxially arranged with thedriving-side rotation body and integrally rotating with a camshaft foropening and closing valves of the internal combustion engine, a fluidpressure chamber formed between the driving-side rotation body and thedriven-side rotation body, the fluid pressure chamber divided into anadvance chamber and a retard chamber by a partition member provided onat least one of the driving-side rotation body and the driven-siderotation body, and a first projecting and retracting member and a secondprojecting and retracting member selectively engaging with thedriving-side rotation body and the driven-side rotation body to lockrelative rotational phase of the driving-side rotation body and thedriven-side rotation body at a predetermined phase or to restrictrelative rotational phase of the driving-side rotation body and thedriven-side rotation body within a predetermined range, the methodcomprising steps of: temporarily fixing the driven-side rotation bodyrelative to the base member in a first rotation restricting state by aprocess of engaging the first projecting and retracting member with thebase member and the driven-side rotation body followed by a process ofrotating either the base member or the driven-side rotation body toestablish a state where the driven-side rotation body rotates in onedirection either in an advance direction or in a retard directionrelative to the base member; providing the supplementary member to thedriven-side rotation body to establish a second rotation restrictingstate by a process of installing the supplementary member to the basemember in a state where the second projecting and retracting memberengages with the supplementary member and the driven-side rotation bodyfollowed by a process of rotating either the supplementary member or thedriven-side rotation body to establish a state where the supplementarymember rotates in said one direction relative to the driven-siderotation body; and fastening the supplementary member and the basemember by a use of a fastening member.
 2. The method of assembling thevariable valve timing apparatus according to claim 1, wherein one of thefirst projecting and retracting member and the second projecting andretracting member is formed in a key form arranged to project andretract in a radial direction of the driving-side rotation body and theother one of the first projecting and retracting member and the secondprojecting and retracting member is formed in a pin form arranged toproject and retract in an axial direction of the driving-side rotationbody.
 3. The method of assembling the variable valve timing apparatusaccording to claim 1, wherein the step of fastening the supplementarymember and the base member by the use of the fastening member follows aprocess of defining a predetermined amount of clearance between thesecond projecting and retracting member and the supplementary member. 4.A method of assembling a variable valve timing apparatus comprising adriving-side rotation body including a first driving-side rotationmember and a second driving-side rotation member, the driving-siderotation body synchronously rotating with a crankshaft of an internalcombustion engine, a driven-side rotation body coaxially arranged withthe driving-side rotation body and integrally rotating with a camshaftfor opening and closing valves of the internal combustion engine, afluid pressure chamber formed between the driving-side rotation body andthe driven-side rotation body, the fluid pressure chamber divided intoan advance chamber and a retard chamber by a partition member providedon at least one of the driving-side rotation body and the driven-siderotation body, and a first projecting and retracting member and a secondprojecting and retracting member selectively engaging with thedriving-side rotation body and the driven-side rotation body to lockrelative rotational phase of the driving-side rotation body and thedriven-side rotation body at a predetermined phase or to restrictrelative rotational phase of the driving-side rotation body and thedriven-side rotation body within a predetermined range, the methodcomprising steps of: temporarily fixing the driven-side rotation body ina first rotation restricting state where rotation of the driven-siderotation body is restricted to one direction relative to the firstdriving-side rotation member following a process of engaging the firstprojecting and retracting member with the first driving-side rotationmember and the driven-side rotation body; providing the driven-siderotation body to the second driving-side rotation member to establish asecond rotation restricting state where rotation of the driven-siderotation body relative to the second driving-side rotation member isrestricted to said one direction or to a direction opposite to said onedirection following a process of installing the second driving-siderotation member to the first driving-side rotation member in a statewhere the second projecting and retracting member engages with thesecond driving-side rotation member and the driven-side rotation body;and fastening the first driving-side rotation member and the seconddriving-side rotation member by a use of a fastening member.
 5. Themethod of assembling the variable valve timing apparatus according toclaim 4, wherein the step of fastening the first driving-side rotationmember and the second driving-side rotation member by the use of thefastening member follows a process of defining a predetermined amount ofclearance between the second projecting and retracting member and thesecond driving-side rotation member.